In Patent Document 1 mentioned below, a fire extinguishing system is disclosed for specifying a fire's point of origin when a fire occurs in various structures such as buildings and tunnels, and performing a rapid, effective, and efficient fire-fighting operation only at the fire's point of origin. In this fire extinguishing system, when the break-out of a fire is detected by a fire detector, a fire's point of origin is specified by an infrared camera which detects infrared rays emitted from flames, and an extinguishing agent is allowed to be discharged to the fire's point of origin from an extinguishing agent discharge nozzle provided in a self-propelled fire extinguishing robot to extinguish the fire.